1. Field of the Invention
The present invention relates to an improvement in an electromotive warping type endoscope apparatus for electrically warping a warp-enabled portion thereof.
2. Description of the Related Art
Recently, endoscopes have been widely used each of which has an elongated insertion portion for use to be inserted into the colon so as to observe the internal organs and, if necessary, capable of performing various curing treatments by using a treatment tool inserted into a treatment-tool channel thereof.
Furthermore, industrial endoscopes have been widely used to observe or inspect internal flaws or corrosion of boilers, gas turbines, pipes of chemical plants and the bodies of automobile engines.
The endoscope of the aforesaid type usually comprises a mechanism for warping a warp-enabled portion formed adjacent to the leading portion thereof and an electric driving means such as a motor for driving the aforesaid warping mechanism. The electromotive warping type endoscope of the aforesaid type is combined with an endoscope, a warp control device for controlling the warping operation of the endoscope and a light source device and the like, so that an electromotive warping type endoscope apparatus is constituted so as to be used practically.
As disclosed in Japanese Patent Laid-Open No. 1-317423, Japanese Patent Laid-Open No. 58-78635, Japanese Patent Publication No. 63-59329 and Japanese Patent Laid-Open No. 58-69523, the electromotive warping type endoscope apparatus of a type having the warp control device provided with a control means for controlling the warping velocity by changing the time in which the warp operation switch is operated, the quantity of the operation of the switch or the power for operating the switch has been disclosed in order to improve the handling facility.
In a case where the endoscope is inserted into the tract or the like, the operator must insert the endoscope while judging the insertion direction of the endoscope and control the warp so as to make the leading portion of the insertion portion face the insertion direction.
However, considerably excellent skill and experience are required when the endoscope is inserted at the time of inspecting the colon or the like.
Accordingly, the applicant of the present invention has disclosed a method in Japanese Patent Application No. 1-23450 which is capable of detecting the direction into which the endoscope is inserted by extracting a dark region included in the endoscope image. Furthermore, in Japanese Patent Application No. 1-24653, the applicant has disclosed a technology in which the direction in which the endoscope is inserted is detected and the warping operation is controlled in such a manner that the leading portion of the insertion portion faces the detected insertion direction.
In a case where the tract is formed straight, it is necessary for the endoscope to simply move forward linearly in the detected insertion direction. However, if the tract is bent, the endoscope must be moved to correspond to the state of bending. However, there has not been a means which is capable of detecting the state of bending of the tract or the like.
Therefore, the applicant of the present invention has suggested an insertion control device in Japanese Patent Application No. 1-270119 which is capable of discriminating the conditions for inserting the endoscope in accordance with the state of a subject of the inspection on the basis of an image signal and therefore capable of automatically inserting the endoscope in a suitable manner according to the state of the subject of the inspection.
In a case where an electronic endoscope or the like is used in the electromotive warping type endoscope apparatus, the warping operation is sometimes performed while observing the monitor image. In this case, the warping velocity is constant regardless of the distance between the subject and the image-sensing means such as the electronic endoscope or the like. Therefore, when the warping is instructed by operating a warping operation switch or the like, the monitor image moves slowly when the aforesaid distance is long and the same moves quickly when the distance is short. As described above, the image moving velocity becomes different due to the distance from the subject, causing a problem to arise in that the warping velocity cannot be easily recognized and therefore the warping operation becomes difficult to perform.
On the other hand, there is a case in which the angle of operation of a warping joy-stick and the angle of warp of the warp-enabled portion does not coincide with each other at the initial operation after the power has been supplied. In this case, there arises a fear that the warp-enabled portion will be warped in an unintentional direction because the operator does not know the fact that the two angles are different from each other.
The conventional electromotive warping type endoscope apparatus is arranged to change the warping velocity by changing the time in which the warping operation is performed, the quantity of the operation, the power for performing the operation or operating the operation switch or the like. However, the state of the insertion portion or that of the warp-enabled portion cannot be recognized and therefore there arises a problem in that the operator must operate the endoscope while always paying attention to prevent contact of the endoscope with the inside wall of the colon.
Although there has been disclosed a structure in Japanese Patent Laid-Open No. 58-69523 which is arranged in such a manner that a switch for finely adjusting the warp is provided in addition to the warp operation switch, the state of the insertion portion or the warp-enabled portion cannot be detected similarly. Therefore, a problem arises in that the operation becomes too complicated because the operator must always pay attention to prevent the contact between the endoscope and the body wall although the operator performs the warping operation while finely moving it by using the aforesaid switch for finely adjusting the warp. What is even worse, there is a risk of injuring the body wall if the warping operation is continued in a state where the endoscope is in contact with the body wall.
The aforesaid insertion control device or the like which has been disclosed in Japanese Patent Application No. 1-270119 and which is capable of automatically inserting the endoscope has no special means for use at the time of the warping operation in the automatic insertion mode.
In the electromotive warping type endoscope apparatus, it is important to know that the warp-enabled portion is straight. For example, in an operation to be performed while observing the monitor image, if the state of straightness can be recognized from only the scope while eliminating the necessity of looking at the warp operation switch or the like, the operator is required to look only at the monitor scope. Therefore, the operability can be improved.
As a related art relating to the operation of warping an endoscope or the like, an apparatus has been disclosed in U.S. Pat. No. 4,941,454 which is arranged in such a manner that a pulse width modulation control is employed to control the operation of pulling a warping cable and controlling the tension.